20258781 has 16 divisors (see below), whose sum is σ = 28787904. Its totient is φ = 12628224.

The previous prime is 20258759. The next prime is 20258813. The reversal of 20258781 is 18785202.

It is not a de Polignac number, because 20258781 - 2¹⁹ = 19734493 is a prime.

It is a super-2 number, since 2×20258781² = 820836415211922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20258281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7095 + ... + 9531.

It is an arithmetic number, because the mean of its divisors is an integer number (1799244).

Almost surely, 2^20258781 is an apocalyptic number.

It is an amenable number.

20258781 is a deficient number, since it is larger than the sum of its proper divisors (8529123).

20258781 is a wasteful number, since it uses less digits than its factorization.

20258781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2620.

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 20258781 is about 4500.9755609201. The cubic root of 20258781 is about 272.6074810980.

The spelling of 20258781 in words is "twenty million, two hundred fifty-eight thousand, seven hundred eighty-one".